Poor dietary patterns are responsible for significant morbidity and mortality in the US and are the greatest modifiable disease risk factor facing Americans. A range of factors conspire to leave racial and ethnic minorities with higher rates of obesity and therefore higher risks for nutrition-related chronic diseases. Nutrition education is a proven method for developing better dietary practices and produces better results when the education is personalized as opposed to a one-size-fits-all approach. Yet communities in low-socioeconomic and rural conditions often lack access to nutrition counseling services. There is a need for scalable, objective dietary assessment methods that can provide personalized dietary feedback, education, and recommendations. Bender Tech (BT) has developed a multiplexed biosensor system capable of rapidly quantifying multiple urinary biomarkers of dietary intake from a home-care setting for personalized nutrition education via its mobile app. We propose to integrate our system into an automated, passive smart-toilet design capable of providing personalized dietary recommendations in a burden-free system for the user accessible to individuals in rural and low socioeconomic conditions alike. SA1: Develop Electrochemical Working Electrode Specific to Sodium: We will combine techniques developed in-house along with techniques from literature to develop electrochemical sensors capable of sensitively and specifically quantifying urinary sodium and add it to our existing multiplexed design. SA2: Eliminate Non-Specific Binding and Interference in Urine Samples: Urine is a complex solution with variable composition of minerals and salts. We will systematically identify and quantify any interference by measuring the response to abundant and/or structurally similar counter-targets and eliminate or minimize contaminating species. SA3: Integrate Sensors and Electronics into Automated and Passive Smart Toilet Design: We will rapidly prototype housing and environmental sensor designs that enable our existing biosensors and electronics to integrate with a home-toilet for automated, passive testing and analysis. A successful outcome of this proposal will be a multiplexed biosensor system capable of rapid and accurate quantification of sodium-to-creatinine ratios in urine from a home-toilet without input from the user. This will ready the product for widespread user-testing and optimization and would be the subject of a future phase II submission.